Design Freeze with Mercedes, page-107

I was just reading the following article:

https://www.triplepundit.com/story/2024/better-lithium-ion-batteries/814181

Someone probably forget to tell Amprius they need to hit 1000 cycles before they can commercialize!

Amprius vs Ultranode: 150 cycles vs 900! and the ultranode is more energy dense and is much cheaper!

Replacing graphite with silicon

Another option is removing graphite altogether and replacing it with a more sustainable, and potentially better-performing, material: silicon.

Silicon isn’t exactly free from environmental impacts because a lot of energy is required to heat silica so it can be processed and turned into battery-grade silicon. The process is, however, friendlier to the environment than graphite production and without some of the social harms associated with mining natural graphite, like poor worker conditions and human rights violations.

Performance-wise, the energy capacity of silicon anode lithium-ion batteries as compared to graphite anode lithium-ion batteries is much, much higher.

“The advantage of silicon over graphite is that one silicon atom can store 4.4 lithium atoms,” said Magda Titirici, chair in the Sustainable Energy Materials Department at the Imperial College London. “In graphite, one lithium gets stored per six carbons.”

With such high energy density, there are some challenges. One is that the lithium-based cathode cannot match the storage capabilities of silicon, and another is that it brings the life cycle of the battery down.

“When we dial up energy density to the maximum today, we typically give it up on the cycle life side,” said Ronnie Tao, vice president of business development at Amprius, a company that produces lithium-ion batteries with silicon anodes. “Our life cycle in those cases is about 100-150 cycles. The unspoken rule for consumer electronics is 500 cycles.”

In terms of costs, silicon anode batteries are more expensive than the graphite versions. But scaling the silicon anode supply chain would likely bring costs below graphite.

“Silicon is literally made out of sand, so it is abundantly available all over the world,” Tao said. “The overall cost would be lower at scale. We’re just not there yet.”

Silicon anode batteries also offer recyclability advantages.

“You could dissolve it in water, and it'll separate out,” Tao said. “It's a much easier process to get a fully recyclable battery.”

Despite the advantages that silicon anode batteries offer, market uptake of this technology is hesitant.

“There are so many things out there that it leads to a lot of market confusion,” Tao said. “Until there's a clear industry focus to move in this direction, it’s kind of hard to grow at scale.”